Support karma-ava

closes #942

This does a few things:

- Moves anything used in child processes that the browser can't replicate into `lib/process-adapter.js` (so that browser implementations can implement that missing functionality).
- Separates out `prefix-title` so `karma-ava` can use it.

It enables use of [`karma-ava`](https://github.com/avajs/karma-ava), which is very preliminary right now, but does work: https://cloud.githubusercontent.com/assets/4082216/16401095/75720328-3caf-11e6-950d-27a9e48bbf9a.png

--

This also includes two commits from #896

index.js

@@ -1,10 +1,9 @@
 'use strict';
-var path = require('path');
-var chalk = require('chalk');
+var process = require('./lib/process-adapter');
 var serializeError = require('./lib/serialize-error');
 var globals = require('./lib/globals');
 var Runner = require('./lib/runner');
-var send = require('./lib/send');
+var send = process.send;
 
 var opts = globals.options;
 var runner = new Runner({
@@ -13,18 +12,6 @@ var runner = new Runner({
 	match: opts.match
 });
 
-// check if the test is being run without AVA cli
-var isForked = typeof process.send === 'function';
-
-if (!isForked) {
-	var fp = path.relative('.', process.argv[1]);
-
-	console.log();
-	console.error('Test files must be run with the AVA CLI:\n\n    ' + chalk.grey.dim('$') + ' ' + chalk.cyan('ava ' + fp) + '\n');
-
-	process.exit(1); // eslint-disable-line xo/no-process-exit
-}
-
 // note that test files have require('ava')
 require('./lib/test-worker').avaRequired = true;
 

lib/fork.js

@@ -6,7 +6,6 @@ var objectAssign = require('object-assign');
 var Promise = require('bluebird');
 var debug = require('debug')('ava');
 var AvaError = require('./ava-error');
-var doSend = require('./send');
 
 if (fs.realpathSync(__filename) !== __filename) {
 	console.warn(
@@ -50,12 +49,16 @@ module.exports = function (file, opts) {
 	var relFile = path.relative('.', file);
 
 	var exiting = false;
-	var send = function (ps, name, data) {
+	var send = function (name, data) {
 		if (!exiting) {
 			// This seems to trigger a Node bug which kills the AVA master process, at
 			// least while running AVA's tests. See
 			// <https://github.com/novemberborn/_ava-tap-crash> for more details.
-			doSend(ps, name, data);
+			ps.send({
+				name: 'ava-' + name,
+				data: data,
+				ava: true
+			});
 		}
 	};
 
@@ -86,7 +89,7 @@ module.exports = function (file, opts) {
 		ps.on('results', function (data) {
 			results = data;
 			data.tests = testResults;
-			send(ps, 'teardown');
+			send('teardown');
 		});
 
 		ps.on('exit', function (code, signal) {
@@ -106,7 +109,7 @@ module.exports = function (file, opts) {
 		});
 
 		ps.on('no-tests', function (data) {
-			send(ps, 'teardown');
+			send('teardown');
 
 			var message = 'No tests found in ' + relFile;
 
@@ -120,13 +123,13 @@ module.exports = function (file, opts) {
 
 	// teardown finished, now exit
 	ps.on('teardown', function () {
-		send(ps, 'exit');
+		send('exit');
 		exiting = true;
 	});
 
 	// uncaught exception in fork, need to exit
 	ps.on('uncaughtException', function () {
-		send(ps, 'teardown');
+		send('teardown');
 	});
 
 	ps.stdout.on('data', function (data) {
@@ -144,13 +147,13 @@ module.exports = function (file, opts) {
 	};
 
 	promise.send = function (name, data) {
-		send(ps, name, data);
+		send(name, data);
 
 		return promise;
 	};
 
 	promise.exit = function () {
-		send(ps, 'init-exit');
+		send('init-exit');
 
 		return promise;
 	};
@@ -164,12 +167,12 @@ module.exports = function (file, opts) {
 
 	promise.run = function (options) {
 		if (isReady) {
-			send(ps, 'run', options);
+			send('run', options);
 			return promise;
 		}
 
 		ps.on('stats', function () {
-			send(ps, 'run', options);
+			send('run', options);
 		});
 
 		return promise;

lib/prefix-title.js

@@ -0,0 +1,25 @@
+'use strict';
+var path = require('path');
+
+module.exports = function (file, base, separator) {
+	var prefix = file
+		.replace(base, function (match, offset) {
+			// only replace this.base if it is found at the start of the path
+			return offset === 0 ? '' : match;
+		})
+		.replace(/\.spec/, '')
+		.replace(/\.test/, '')
+		.replace(/test\-/g, '')
+		.replace(/\.js$/, '')
+		.split(path.sep)
+		.filter(function (p) {
+			return p !== '__tests__';
+		})
+		.join(separator);
+
+	if (prefix.length > 0) {
+		prefix += separator;
+	}
+
+	return prefix;
+};

lib/process-adapter.js

@@ -0,0 +1,107 @@
+'use strict';
+var fs = require('fs');
+var path = require('path');
+var chalk = require('chalk');
+var sourceMapSupport = require('source-map-support');
+var installPrecompiler = require('require-precompiled');
+
+var debug = require('debug')('ava');
+
+// check if the test is being run without AVA cli
+var isForked = typeof process.send === 'function';
+
+if (!isForked) {
+	var fp = path.relative('.', process.argv[1]);
+
+	console.log();
+	console.error('Test files must be run with the AVA CLI:\n\n    ' + chalk.grey.dim('$') + ' ' + chalk.cyan('ava ' + fp) + '\n');
+
+	process.exit(1); // eslint-disable-line xo/no-process-exit
+}
+
+exports.send = function (name, data) {
+	process.send({
+		name: 'ava-' + name,
+		data: data,
+		ava: true
+	});
+};
+
+exports.on = process.on.bind(process);
+exports.emit = process.emit.bind(process);
+exports.exit = process.exit.bind(process);
+exports.env = process.env;
+
+var opts = exports.opts = JSON.parse(process.argv[2]);
+
+// Fake TTY support
+if (opts.tty) {
+	process.stdout.isTTY = true;
+	process.stdout.columns = opts.tty.columns || 80;
+	process.stdout.rows = opts.tty.rows;
+
+	var tty = require('tty');
+	var isatty = tty.isatty;
+
+	tty.isatty = function (fd) {
+		if (fd === 1 || fd === process.stdout) {
+			return true;
+		}
+
+		return isatty(fd);
+	};
+}
+
+if (debug.enabled) {
+	// Forward the `time-require` `--sorted` flag.
+	// Intended for internal optimization tests only.
+	if (opts._sorted) {
+		process.argv.push('--sorted');
+	}
+
+	require('time-require');
+}
+
+var sourceMapCache = Object.create(null);
+var cacheDir = opts.cacheDir;
+
+exports.installSourceMapSupport = function () {
+	sourceMapSupport.install({
+		environment: 'node',
+		handleUncaughtExceptions: false,
+		retrieveSourceMap: function (source) {
+			if (sourceMapCache[source]) {
+				return {
+					url: source,
+					map: fs.readFileSync(sourceMapCache[source], 'utf8')
+				};
+			}
+		}
+	});
+};
+
+exports.installPrecompilerHook = function () {
+	installPrecompiler(function (filename) {
+		var precompiled = opts.precompiled[filename];
+
+		if (precompiled) {
+			sourceMapCache[filename] = path.join(cacheDir, precompiled + '.js.map');
+			return fs.readFileSync(path.join(cacheDir, precompiled + '.js'), 'utf8');
+		}
+
+		return null;
+	});
+};
+
+exports.installDependencyTracking = function (dependencies, testPath) {
+	Object.keys(require.extensions).forEach(function (ext) {
+		var wrappedHandler = require.extensions[ext];
+		require.extensions[ext] = function (module, filename) {
+			if (filename !== testPath) {
+				dependencies.push(filename);
+			}
+
+			wrappedHandler(module, filename);
+		};
+	});
+};

lib/run-status.js

@@ -1,11 +1,11 @@
 'use strict';
 var EventEmitter = require('events').EventEmitter;
-var path = require('path');
 var util = require('util');
 var chalk = require('chalk');
 var isObj = require('is-obj');
 var flatten = require('arr-flatten');
 var figures = require('figures');
+var prefixTitle = require('./prefix-title');
 
 function RunStatus(opts) {
 	if (!(this instanceof RunStatus)) {
@@ -128,26 +128,7 @@ RunStatus.prototype.prefixTitle = function (file) {
 
 	var separator = ' ' + chalk.gray.dim(figures.pointerSmall) + ' ';
 
-	var prefix = path.relative('.', file)
-		.replace(this.base, function (match, offset) {
-			// only replace this.base if it is found at the start of the path
-			return offset === 0 ? '' : match;
-		})
-		.replace(/\.spec/, '')
-		.replace(/\.test/, '')
-		.replace(/test\-/g, '')
-		.replace(/\.js$/, '')
-		.split(path.sep)
-		.filter(function (p) {
-			return p !== '__tests__';
-		})
-		.join(separator);
-
-	if (prefix.length > 0) {
-		prefix += separator;
-	}
-
-	return prefix;
+	return prefixTitle(file, this.base, separator);
 };
 
 RunStatus.prototype.handleOutput = function (channel, data) {